I have a brand new Arduino Yun (rev 2) board powered by a micro USB cable connected to a laptop. It is working fine, but I noticed that the linux chip on the board gets *very* hot to the touch (I can only stand to keep my finger pressed against it for a few seconds before I need to pull away). I realize this board does much more than the Uno boards I have used in the past, but is this degree of heat generation normal? I am worried about protecting things that come in proximity to the under-surface of the board.